REAPER – Tint Background Color Track – Add a toolbar button
Right click on the grey area of the Toolbar and choose “Customize toolbar…”
Click “Add…”
Filter for the word “color”
Select “Track: Set to random colors” or “Track: Set to custom color…”
Click Select, After you can specify an “Icon…” if you would like.
You can always right click on selected Tracks and select “Track color – Set tracks to default color”

— REAPER customize shortcuts —

Shortcuts can be change in the Preference Option window
Ctrl+p = open preference window
General – Keyboard/Multitouch – Click on “Assign keyboard to actions or change existing shortcuts”

Add Shortcut to Frame All – Main section
Filter for the word “zoom”
Click on “View: Zoom time selection”
Click on “Add…”, Suggested shortcut = “A”